Personal audio devices including, without limitation, mobile/cellular telephones, smart phones, palmtop computers, personal digital assistants, tablet devices, portable media players including MP3 players, and other consumer audio devices are in widespread use. Such personal audio devices may include audio signal processing circuitry for generating an analog audio output signal suitable for driving one or more external or internal speakers. Audio signal processing circuitry may include various components that inherently contribute corresponding noise components to the audio output signal.
The relative significance of these various noise components may vary depending upon playback conditions or factors including, without limitation, a volume level selected by a user and a magnitude or amplitude of a digital audio signal provided to or generated within the audio processing circuitry. The noise associated with at least some components may be amplified or attenuated by a power amplifier and the amplified or attenuated noise may contribute to the total noise floor of the analog audio output signal.
Power consumption is a critical metric for any hand held, mobile, or wireless electronic device because its power consumption is a direct determinant of how long the device may be operated before it is necessary to recharge the device's battery. Generally, however, power consumption increases as performance parameters including, without limitation, signal-to-noise ratio, increase. As a result, desirable power consumption reductions may be associated with reduced or degraded performance parameters.